The present invention relates generally to nonimpact printing heads, and in particular to a novel ink jet printing head in which the effects of air pressure gradient and electric field are combined to form a jet stream of ink droplets.
It is known in the art to utilize electric field potentials to form a jet stream of ink droplets. The ink jet printer of this type comprises a plate electrode on which recording medium is placed. A liquid nozzle is pointed toward the electrode and biased negative with respect to the electrode. By a strong concentration of field at the meniscus of the liquid, the latter is attracted toward the electrode and torn apart into a droplet which is pulled toward the electrode and creates an image on the recording medium. However, the conventional system requires a considerably high operating voltage and results in a relatively large construction which makes it difficult to achieve multiple nozzle design for high speed printing.